Clearly the 6.14 Taliyah changes have failed.
According to this website, Taliyah's win rate from patch 6.13 to patch 6.14 has dropped form around 52% to around 46%. I understand that the changes in 6.14 were meant to make the champion easier to play, but they just took away her "hard to master, but then hard to beat" status. I used to main Taliyah shortly after launch when she was a disruption mage with hard yet rewarding playstyle but now she's just a mediocre combo mage who pails in comparison to the likes of Brand, Xerath, and Vel'Koz. I would say that its better to have a hard champion than a bad champion. Its ok if there isn't a lot of people playing her, people are naturally going to be attracted to what they can do the best with while inputting minimal effort. Making her have a more simple and less effective playstyle just makes her appeal to even less people.